BAQOUBA, Iraq — A U.S. effort to recruit former Sunni insurgents north of Baghdad — considered crucial to expanding the fight against extremists — is in danger of collapse because the government has been unable or unwilling to accept the volunteers into Iraqi security forces.

The potential breakdown in Diyala — described by U.S. and Iraqi officials in interviews this week — underscores the challenges of copying the military-militia alliances that uprooted al-Qaida in Iraq and other factions from strongholds in Iraq’s western desert.

It also could threaten some of the gains of the U.S.-led security crackdown in Baghdad and surrounding areas, including the important battleground of Diyala where al-Qaida in Iraq claims the capital Baqouba as its base.

In Diyala, more than 2,200 former militants have renounced the terror network and teamed with U.S. soldiers. But American officials fear the volunteers could halt cooperation if the Iraqi government continues to deny them police jobs.

The Interior Ministry says it’s about numbers. It has capped Diyala’s force at 13,000 — which is already over the limit — meaning there is no room for the “concerned local nationals,” known as CLNs.

But there are accusations that Iraq’s sectarian rifts are playing a role.

In the western province of Anbar — nearly all Sunni — there have been few problems incorporating the new allies against al-Qaida into security forces. Diyala, however, is mixed between Sunnis and Shiites. Some CLN members claim the Shiite-led government is worried about handing Sunnis too much influence and power in the province.

“I want to stop the river of blood that’s run through my neighborhood and my country, but I want to do that with recognition from the government and status as a policeman,” said Omar Abdullah, 19, who joined the CLN three months ago during a major U.S. offensive in Baqouba.

Abdullah kicked the ground in frustration outside a safe house, where the volunteers wear yellow reflective sashes marking them as U.S. allies.

U.S. and Iraqi officials say 5,000 more Iraqi police are needed in Diyala, one of the most dangerous parts of Iraq for U.S. and government forces. Prime Minister Nouri al-Maliki also endorsed the idea of incorporating the volunteers into Diyala’s security forces when he visited Baqouba in July.

“If I could, I’d hire 1,000 more CLNs in Baqouba alone, but my hands are tied,” said Gen. Ghanim al-Qureyshi, director general of Diyala police. “The central government will not give me the budget,” he added with a shrug.

About 600 ex-insurgents were hired as policemen earlier this year, before the force reached capacity, officials said.

On Sept. 17, thousands of the former insurgents and their supporters marched peacefully through Baqouba, calling for al-Qureyshi’s resignation and chanting they would “sacrifice ourselves and our blood to you, Saddam.” Many are members of the 1920s Revolution Brigades, a group of Saddam Hussein loyalists involved in the insurgency early in the war.

The demonstrators marched a day after a CLN member was killed in a gunfight with Iraqi police, who are suspicious of the group because of its members’ previous ties to the Sunni insurgency.

On Sunday, some former 1920s members surrounded an Iraqi police station in Baqouba’s Tahrir neighborhood and tried to steal a truck filled with food and supplies, al-Qureyshi said. No one was injured, but the standoff illustrated the growing friction and desperation of the fighters who feel cast adrift and are without backing to support their families.

“I worry this (tension) is going to explode, and we’ll revert back to these individuals supporting al-Qaida,” said Col. David Sutherland, the U.S. military commander in Diyala province. “It weighs heavily on my mind.”